The invention relates to an electric lamp provided with a lamp vessel which is made of glass with an SiO.sub.2 content of at least 95% by weight, in which an electric element is arranged, and which has an axis and a seal, and
current conductors enclosed in the seal, each comprising a metal foil connected to a conductor issuing from the seal to the exterior and to a conductor extending to the electric element,
which metal foils are each arranged in their own plane parallel to the axis of the lamp vessel.
Such an electric lamp is known from GB 2 103 872 A. The known lamp has a rotationally symmetrical fused seal. The seal was obtained in that a glass tube closed at one end or a glass rod was inserted into a tube present at the lamp vessel under construction, together with the current conductors which are arranged diametrically opposite one another. The glass tube at the lamp vessel is then heated above its softening temperature to cause it to collapse onto the metal foils.
An important disadvantage of the known lamp is that the glass tube at the lamp vessel is heated to above its softening temperature, but the glass tube or rod present therein is not. The tube at the lamp vessel in fact screens the glass tube or rod from the heat source. As a result, this latter tube or rod does not reach its softening temperature and no fusion takes place between the two glass bodies, so there will be no or a poor adhesion of the tube or rod to the metal foils. Accordingly, there is a considerable risk that the lamp will be leaky.
Another disadvantage is the complicated construction which requires much glass. The lamp has the advantage, however, that the current conductors issue from the seal to the exterior and into the lamp vessel comparatively far removed from one another. The risk of flash-over between the current conductors at comparatively high voltages is counteracted thereby.
The risk of flash-over exists, for example, in the electric lamp of GB 1 102 646 in which the metal foils are in a stacked arrangement in a pinch seal with glass interposed. The foils may be comparatively wide, and thus carry a comparatively strong current, but they lie close together, as do the conductors connected thereto.
Other electric lamps such as, for example, those known from DE 25 44 134 C2, have diametrically opposed seals through which respective current conductors extend. Flash-over outside the lamp is practically impossible as a result, but the lamp has the disadvantage that it must be connected to a supply source in two locations remote from one another and will often require two lamp caps. When the lamp is used in a reflector, for example, inconvenient shadows may be formed when a conductor returns between the lamp and the reflector from a first sea/to a second seal in order to be connected to a lamp cap together with another conductor issuing from said second seal.